".c2addon" - https://www.scirra.com/forum/how-to-install-plugins-and-behaviors_t63985
But what sinistar proposes here is a file that compiles "all plugins".
I don't personally use a lot of plugins, or see there use of a good eye. A lot of people tend to use them as a bandaid instead of learning how to do things through events.
It also adds the inconvenience that when you later ask a question and post your capx in the forums, using plugins, people have to have the same plugins installed in order to open the capx and answer the question, which is, most of the time, a huge PIA.
Moreover, all plugins are not necessary for everyone.
That is my personal opinion though, and if a majority of persons are in favor, perhaps such a package should be made.